In recent years, for example, as shown in Patent Documents 1 to 4, wireless power-supplying systems configured to wirelessly supply power from a power-supplying-side coil (power-supplying coil) to a power-receiving-side coil (power-receiving coil) have been used. For example, technology for supplying power to a battery mounted on a vehicle such as an electric vehicle (EV) or a hybrid vehicle (HV) using the wireless power-supplying systems has been proposed.